The University of Colorado at Boulder's Renewable and Sustainable Energy Institute, or RASEI -- a joint venture with the U.S. Department of Energy's National Renewable Energy Laboratory -- will partner with Toyota Motor Sales U.S.A. Inc. in a field study of household experiences and the technical impacts of plug-in hybrid electric vehicles, or PHVs, in a "smart grid" environment.

Toyota Motor Sales will supply 18 Prius PHVs for the two-year program. The cars, which are slated to arrive in mid-September, will be circulated in three-month stints among 108 randomly selected Boulder households that volunteered to be part of "smart grid" pilot tests.

"This is a great example of CU working together with industry to address big-picture energy questions," said Michael Knotek, director of RASEI. "RASEI is here to make a real-world impact. With these partnerships and our smart grid' research expertise, we'll be able to get some new insights into the intersection of transportation and the electric grid."

RASEI and Toyota Motor Sales, with the integral participation of Xcel Energy, will gather data on vehicle performance and electricity usage, as well as how households interact with vehicle feedback through "smart grid" technology. The Boulder location also presents the opportunity for researchers to monitor the performance of Toyota's first-generation lithium-ion battery at high altitudes and in cold weather.

The 18 vehicles being used in the field study are part of a 150-vehicle demonstration program that Toyota Motor Sales is conducting throughout the United States.

The Prius PHV can be charged in approximately three hours from a standard 110-volt electrical outlet, or in one and a half hours with a 220-volt electrical outlet, and can cruise in electric-only mode for approximately 13 miles. For longer distances, the PHV reverts to its hybrid mode and operates like a regular Prius.